net, ip6_tunnel: enhance tunnel locate with link check
With ipip, it is possible to create an extra interface explicitly
attached to a given physical interface:
# ip link show tunl0
4: tunl0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ipip 0.0.0.0 brd 0.0.0.0
# ip link add tunl1 type ipip dev eth0
# ip link show tunl1
6: tunl1@eth0: <NOARP> mtu 1480 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ipip 0.0.0.0 brd 0.0.0.0
But it is not possible with ip6tnl:
# ip link show ip6tnl0
5: ip6tnl0@NONE: <NOARP> mtu 1452 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/tunnel6 :: brd ::
# ip link add ip6tnl1 type ip6tnl dev eth0
RTNETLINK answers: File exists
This patch aims to make it possible by adding link comparaison in both
tunnel locate and lookup functions; we also modify mtu calculation when
attached to an interface with a lower mtu.
This permits to make use of x-netns communication by moving the newly
created tunnel in a given netns.
Signed-off-by: William Dauchy <w.dauchy@criteo.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed
